The advise to use maracyn (erythromycin) is not so much wrong advice as it is old advice. All of the "anti-cyanobacteria" treatments used to be some type of antibiotic. I think I still have some old books that recommend this, along with using undergravel filters. Things have changed alot but for some reason it takes a long time for old advise to go away in this industry. I would bet money that in 10 years the "Do I need to use Bio Balls on a reef tank" question will still be commonly asked on MAAST. The best rule of thumb is - No medications in your main tank.

Gary is right on about the phosphates. This is a problem I here from customers several times a week so I would recommend the following:
1st - Get your water tested for phosphate. Just keep in mind that hobbyist grade phosphate test kits won't read all forms of phosphate so if it reads zero and you have an algae problem...you still have a phosphate problem. So why bother to get your water tested? If you get a reading of say .2ppm - 1.0ppm then chances are you have built up some phosphates in the normal course of setting up a new tank or through normal feeding. If you get a reading much greater than 1.0ppm then it's time to start looking at additional sources of phophates (i.e. make up water, additives, over feeding etc.). I'm sure there are exceptions but IME algae problems are always a result of a phosphate problem.

2nd - If it's a fairly new tank, start using Phosguard regulary. Hopefully you have set the tank up so that you have some form of nutrient export ( DSB, sufficient live rock, refugium, macroalgaes etc.) but these take some time to fully develop and Phosguard will help keep things under control in the meantime. Rowa Phos is a newer product which I've been told is more efficient than phosguard although I have not yet tried it. Regardless of which product, it is ultimately way too expensive to control phosphates strictly with chemicals so some form of nutrient export is definitely the way to go.

As Tim said you will never have an algae free tank but since you were considering using antibiotics I'm assuming you have more than the usual amount of algae. Clean up crews are great for keeping things tidy but if you clean up the tank only to have it completely covered again two or three days later I would go for phosphate control approach plus some number of clean up critters (just not the 5 per ml or whatever the crazy number is that some places recommend). A quick fix that has worked well for me is to use phosguard along with chemi clean, if your phosphates aren't too out of control the cyanobacteria will be gone in a day or two and won't come back -well at least not until your phosphate gets too high again.